Allyl bromide

{{chembox

| Watchedfields = changed

| verifiedrevid = 477314323

| ImageFile = 3-Brompropen.svg

| ImageSize = 180px

| ImageName = Skeletal formula

| ImageFile1 = Allyl-bromide-3D-balls-B.png

| ImageName1 = Ball-and-stick model

| PIN = 3-Bromoprop-1-ene

| OtherNames = Allyl bromide
3-Bromopropene
3-Bromopropylene
3-Bromo-1-propene
Bromoallylene
2-Propenyl bromide

|Section1={{Chembox Identifiers

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 7553

| InChIKey = BHELZAPQIKSEDF-UHFFFAOYAI

| SMILES1 = C=CCBr

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/C3H5Br/c1-2-3-4/h2H,1,3H2

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = BHELZAPQIKSEDF-UHFFFAOYSA-N

| CASNo_Ref = {{cascite|correct|CAS}}

| CASNo = 106-95-6

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = FXQ8X2F74Z

| EINECS = 203-446-6

| PubChem = 7841

| SMILES = BrCC=C

| InChI = 1/C3H5Br/c1-2-3-4/h2H,1,3H2

| RTECS = UC7090000

| UNNumber = 1099

}}

|Section2={{Chembox Properties

| C=3|H=5|Br=1

| Appearance = Clear to light yellow liquid

| Odor = Unpleasant, irritating, pungent

| Density = 1.398 g/cm3

| MeltingPtC = −119

| MeltingPt_notes =

| BoilingPtC = 71

| BoilingPt_notes =

| Solubility = 0.38 g/100 g H2O

| RefractIndex = 1.4697 (20 °C, 589.2 nm)

| MagSus = −58.6·10−6 cm3·mol−1{{Cite book |url=https://www.worldcat.org/oclc/930681942 |title=CRC handbook of chemistry and physics : a ready-reference book of chemical and physical data. |date=2016 |first1=William M.|last1= Haynes|first2= David R.|last2= Lide|first3= Thomas J.|last3= Bruno |isbn=978-1-4987-5428-6 |edition=2016-2017, 97th |location=Boca Raton, Florida |oclc=930681942}}

| LogP = 1.79

| Viscosity = 0.471 cP

| VaporPressure = 18.6 kPa

| Dipole = ≈1.9 D

}}

| Section4 = {{Chembox Thermochemistry

| DeltaHform = 12.2 kJ·mol−1 (liquid)
45.2 kJ·mol−1 (gas)

| DeltaHvap = 32.73 kJ·mol−1

}}

|Section7={{Chembox Hazards

| ExternalSDS = [http://ptcl.chem.ox.ac.uk/MSDS/BR/3-bromopropene.html MSDS at Oxford University]

| MainHazards =

| FlashPt = −2 to −1 °C

| AutoignitionPtC = 280

| NFPA-H = 3

| NFPA-F = 3

| NFPA-R = 1

| NFPA-S =

| GHSPictograms = {{GHS02}}{{GHS05}}{{GHS06}}{{GHS08}}{{GHS09}}

| GHSSignalWord = Danger

| HPhrases = {{H-phrases|225|301|314|330|331|340|350|400}}

| PPhrases = {{P-phrases|201|202|210|233|240|241|242|243|260|261|264|270|271|273|280|281|284|301+310|301+330+331|303+361+353|304+340|305+351+338|308+313|310|311|320|321|330|363|370+378|391|403+233|403+235|405|501}}

| ExploLimits = 4.3–7.3 %

| TLV-TWA = 0.1 ppm

| TLV-STEL = 0.2 ppm

}}

| Section8 = {{Chembox Related

| OtherCompounds = Allyl chloride
Allyl iodide

}}

}}

Allyl bromide (3-bromopropene) is an organic halide. It is an alkylating agent used in synthesis of polymers, pharmaceuticals, perfumes{{Cite web |last=PubChem |title=Hazardous Substances Data Bank (HSDB) : 622 |url=https://pubchem.ncbi.nlm.nih.gov/source/hsdb/622#section=Manufacturing-Use-Information |access-date=2022-03-04 |website=pubchem.ncbi.nlm.nih.gov |language=en}} and other organic compounds. Allyl bromide is a colorless liquid, although commercial samples appear yellow or brown. It is an irritant and a potentially dangerous alkylating agent. Allyl bromide is more reactive but more expensive than allyl chloride, and these considerations guide its use.{{cite book| doi = 10.1002/14356007.a04_405.pub2| chapter = Bromine Compounds| title = Ullmann's Encyclopedia of Industrial Chemistry| date = 2013| last1 = Yoffe| first1 = David| last2 = Frim| first2 = Ron| last3 = Ukeles| first3 = Shmuel D.| last4 = Dagani| first4 = Michael J.| last5 = Barda| first5 = Henry J.| last6 = Benya| first6 = Theodore J.| last7 = Sanders| first7 = David C.| pages = 1–31| isbn = 978-3-527-30385-4}}

Preparation

= Hydrohalogenation =

Allyl bromide is produced commercially from allyl alcohol and hydrobromic acid:

:CH2=CHCH2OH + HBr → CH2=CHCH2Br + H2O

It can also be prepared by the halogen-exchange reaction between allyl chloride and hydrobromic acid or by the allylic bromination of propene.

Reactions and uses

Allyl bromide is an electrophilic alkylating agent.{{Citation |last=Bolton |first=Roger |title=Allyl Bromide |date=2001-04-15 |url=https://onlinelibrary.wiley.com/doi/10.1002/047084289X.ra045 |encyclopedia=Encyclopedia of Reagents for Organic Synthesis |pages=ra045 |editor-last=John Wiley & Sons, Ltd |place=Chichester, UK |publisher=John Wiley & Sons, Ltd |language=en |doi=10.1002/047084289x.ra045 |isbn=978-0-471-93623-7 |access-date=2022-03-04}} It reacts with nucleophiles, such as amines, carbanions, alkoxides, etc., to introduce the allyl group:

:CH2=CHCH2Br + Nu → CH2=CHCH2Nu + Br (Nu is a nucleophile)

It is used in the synthesis of compounds containing the allyl functionality, such as the pharmaceuticals methohexital, secobarbital and thiamylal.

Allyl bromide reacts with magnesium metal in dry ether to form allylmagnesium bromide, a Grignard reagent:{{Cite journal |date=1999 |url=http://orgsyn.org/demo.aspx?prep=V76P0221 |journal=Organic Syntheses |volume=76 |pages=221 |doi=10.15227/orgsyn.076.0221|title=6-Chloro-1-Hexene and 8-Chloro-1-Octene|first1=Pierre|last1= Mazerolles|first2= Paul |last2=Boussaguet|first3= Vincent|last3= Huc }}

:CH2=CHCH2Br + Mg → CH2=CHCH2MgBr

:

References

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